CN108612852B

CN108612852B - Valve seat and valve structure

Info

Publication number: CN108612852B
Application number: CN201710569221.4A
Authority: CN
Inventors: 小川吉雄
Original assignee: Iwaki Co Ltd
Current assignee: Iwaki Co Ltd
Priority date: 2016-12-13
Filing date: 2017-07-13
Publication date: 2021-05-07
Anticipated expiration: 2037-07-13
Also published as: EP3557099B1; EP3557099A1; WO2018109839A1; CN207005305U; DK3557099T3; US10941868B2; JPWO2018109839A1; CN108612852A; JP6739545B2; US20190390778A1; EP3557099A4

Abstract

The present invention provides a valve seat disposed below a valve ball, the valve seat being formed of an annular member in which a seating surface and a lower end surface of the valve ball are formed into a circular shape, a flow path through which a carrier fluid containing a gas and a liquid flows being provided between the seating surface and the lower end surface, the flow path being formed into a predetermined shape in which a horizontal distance from a central axis perpendicular to the lower end surface to a flow path inner circumferential surface other than the seating surface and the lower end surface is not constant over an entire circumferential range of the flow path.

Description

Valve seat and valve structure

Technical Field

The invention relates to a valve seat and a valve structure.

Background

Various pump devices such as an electromagnetic pump device, a fixed displacement pump device, and a rotary displacement pump device are known as pump devices for conveying a conveying fluid. Among them, for example, a reciprocating pump as a constant-displacement pump device employs ball valves as a suction valve and a discharge valve, and introduces a transport fluid into a pump chamber through the suction valve by reciprocating motion of a reciprocating member such as a diaphragm, and discharges the transport fluid from the pump chamber through the discharge valve. It is known that the ball valve is in a gas-closed state when gas generated by feeding fluid into the pump chamber and gas such as air sucked together with the fed fluid are accumulated in a lower portion of the valve.

In order to prevent such gas lock, a reciprocating pump including an automatic exhaust mechanism has been proposed (see patent document 1 below). In this reciprocating pump, a passage immediately after the discharge valve is branched into a discharge liquid passage extending horizontally to the discharge port and an exhaust passage extending upward. An exhaust valve is disposed in the exhaust passage, and the exhaust valve is constituted by a single ball valve and valve seats disposed above and below the ball valve.

The exhaust valve is designed to be an incomplete seal in which the sealing between the valve ball and the valve seat above the valve ball is intentionally poor. Therefore, the liquid or gas can be prevented from leaking from the outside through the valve ball and the valve seat on the lower side during the suction stroke, like a general ball-type shutoff valve. On the contrary, during the discharge stroke, a small amount of gas mixed in the liquid is efficiently discharged to the outside through the incomplete seal between the valve ball and the upper valve seat.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 9-203380

Disclosure of Invention

Technical problem to be solved by the invention

However, in the reciprocating pump of the prior art disclosed in the above patent document 1, the valve ball and the upper valve seat form an incomplete seal. Therefore, although this is a preferable embodiment from the viewpoint of preventing gas lock, it is hardly said that this is a preferable embodiment from the viewpoint of the sealing property of the valve ball.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a valve seat and a valve structure that can prevent gas lock while maintaining the sealing performance of a valve ball.

Means for solving the problems

A valve seat according to the present invention is a valve seat disposed below a valve ball, the valve seat being formed of an annular member having a hole in the center, the hole serving as a flow path through which a fluid flows, the valve seat being provided such that a central axis of the hole faces in the vertical direction, and the valve seat having a seating surface connected to an upper end of the hole and a lower end surface connected to a lower end of the hole, the seating surface conforming to an outer shape of the valve ball and on which the valve ball is seated, the hole being formed in a predetermined shape such that a horizontal distance from the central axis to an inner circumferential surface of the hole is not constant over the entire circumferential range of the inner circumferential surface of the hole.

In one embodiment of the present invention, the predetermined shape is a shape in which a difference between a maximum value and a minimum value of the horizontal distance over an entire circumference of the inner circumferential surface of the hole is 10% or more and 30% or less from the maximum value.

In another embodiment of the present invention, the predetermined shape is any one of a partially deformed circular shape, an elliptical shape, a water drop shape, a snare drum shape, an eccentric circular shape, an overlapped circular shape, a cross shape, a square shape, and a triangular shape when viewed in a horizontal cross section.

The valve structure according to the present invention includes: a valve ball, a valve seat arranged below the valve ball, and a valve seat support for supporting the valve seat, wherein the valve seat is formed by an annular component with a hole part in the center, the hole portion is a valve seat flow path through which a transport fluid flows, the valve seat is provided so that a central axis of the hole portion faces in a vertical direction, and has a seating surface connected to an upper end of the hole portion and a lower end surface connected to a lower end of the hole portion, the seating surface conforms to the contour of the valve ball and the valve ball seats thereon, the valve seat having a seat flow path communicating with the valve seat flow path, the hole is formed in a predetermined shape in which a horizontal distance from the central axis to an inner peripheral surface of the hole is not constant over an entire circumferential range of the inner peripheral surface of the hole, the holder flow path has a plurality of ribs protruding from an inner peripheral surface of the holder flow path toward the center axis and extending along the center axis.

In another embodiment of the present invention, two valve balls are disposed vertically, the valve seats are disposed below the respective valve balls, and the valve seat holder supports a lower end surface of the lower valve seat.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the occurrence of gas lock can be prevented while maintaining the sealing performance of the valve ball.

Drawings

Fig. 1 is a sectional view showing a main part of a reciprocating pump using a valve seat and a valve structure according to an embodiment of the present invention.

Fig. 2 is a perspective view showing a valve seat of the reciprocating pump.

Fig. 3 is a plan view showing the valve seat.

Fig. 4 is a sectional view taken along line a-a' of fig. 3.

Fig. 5 is a sectional view taken along line B-B' of fig. 3.

Fig. 6 is a plan view showing a valve seat support of the reciprocating pump.

Fig. 7 is a sectional view taken along line C-C' of fig. 6.

Fig. 8 is a plan view showing a modification of the valve seat.

Fig. 9 is a plan view showing a modification of the valve seat.

Fig. 10 is a plan view showing a modification of the valve seat.

Fig. 11 is a plan view showing a modification of the valve seat.

Fig. 12 is a plan view showing a modification of the valve seat.

Fig. 13 is a plan view showing a modification of the valve seat.

Fig. 14 is a plan view showing a modification of the valve seat.

Fig. 15 is a plan view showing a modification of the valve seat.

Detailed Description

Hereinafter, a valve seat and a valve structure according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the following embodiments do not limit the inventions according to the claims, and not all combinations of the features described in the embodiments are essential to the solving means of the invention. In the following embodiments, the valve structure according to the present invention is applied to the intake valve and the discharge valve to constitute the fixed displacement pump, and the valve seat according to the present invention is included as a constituent member of the pump.

Fig. 1 is a sectional view showing a main part of a reciprocating pump using a valve seat 50 and a valve structure according to an embodiment of the present invention. Fig. 2 is a perspective view showing a valve seat 50 of the reciprocating pump, and fig. 3 is a plan view showing the valve seat 50. In addition, fig. 4 is a sectional view taken along line a-a 'of fig. 3, and fig. 5 is a sectional view taken along line B-B' of fig. 3. Further, fig. 6 is a plan view showing the valve seat support 40 of the reciprocating pump, and fig. 7 is a sectional view taken along line C-C' of fig. 6.

As shown in fig. 1, a fixed displacement pump 1 including a valve seat 50 and a valve structure according to an embodiment of the present invention includes, for example, a rod-shaped drive shaft 2. The drive shaft 2 is reciprocally driven in the direction indicated by the arrow in the figure by a motor driving force, an electromagnetic force, or the like of a pump main body, not shown. A flexible diaphragm 4 is attached to the front end of the drive shaft 2 by an insertion bolt 3.

A pump chamber 6 is formed between the diaphragm 4 and the pump head 5. A transport fluid containing a liquid and a gas is introduced into or discharged from the pump chamber 6. The peripheral edge of the diaphragm 4 is sandwiched between the pump head 5 and the bracket 7 with a cushion material 7a and a gasket 7b that contribute to sealing of the diaphragm 4. The pump head 5 is provided with an intake port 5a communicating with the lower side of the pump chamber 6 and a discharge port 5b communicating with the upper side of the pump chamber 6. An exhaust passage 90 connected to the discharge port 5b is provided above the pump chamber 6.

The pump head 5 is provided with a connection port 8 on the suction side, which is disposed below the suction port 5a and through which fluid is conveyed, and a connection port 9 on the discharge side, which is disposed above the discharge port 5 b. The

connection ports

8 and 9 communicate with the pump chamber 6 through the suction port 5a and the discharge port 5b, respectively. The

connection adapters

20A, 20B are connected to the

connection ports

8, 9 via the suction valve 10A and the discharge valve 10B, respectively.

The connection joints 20A and 20B are connected to a joint 29A and a joint 29B, respectively, the joint 29A connecting the suction-side channel 29A of the carrier fluid to the connection joint 20A, and the joint 29B connecting the discharge-side channel 29B of the carrier fluid to the connection joint 20B. Thereby, the suction-side flow path 29A and the pump chamber 6 are connected by the joint 29A, the connection adapter 20A, the suction valve 10A, and the suction port 5a on the connection port 8. The discharge-side flow path 29B and the pump chamber 6 are connected by the joint 29B, the connection adapter 20B, the discharge valve 10B, and the discharge port 5B below the connection port 9.

The suction valve 10A and the discharge valve 10B include: for example, the valve includes

housings

30a and 30b formed in a cylindrical shape and vertically combined, and two

valve balls

31a and 31b built in the

housings

30a and 30 b. The suction and

discharge valves

10A and 10B are provided inside the housings 30A and 30B, and include valve guides 32a and 32B disposed above the respective valve balls 31a and 31B, and valve seats 50 disposed below the valve balls 31a and 31B and attached to the housings 30A and 30B. Therefore, the suction and

discharge valves

10A and 10B of the present embodiment are formed of two-stage ball valves in which these members are disposed in two stages, one above the other. The suction valve 10A and the discharge valve 10B each include a valve seat holder 40 that supports a lower valve seat 50 and is attached to the lower end side of the housing 30B.

The

valve balls

31a, 31b can be made of a material having a specific gravity higher than that of the fluid to be transported, such as ceramic or metal. The valve guides 32a and 32b can be made of titanium, PVC, or other material. Further, the valve seat 50 may be formed of a rubber material or the like.

As shown in fig. 2 to 5, the valve seat 50 is formed of an annular member having a hole 54a at the center and having an outer diameter that increases from the upper end to the lower end. The valve seat 50 includes: the circular planar upper end surface 51 is formed as a tapered or conical seating surface 52 that conforms to the outer shape of the

valve balls

31a and 31b and on which the

valve balls

31a and 31b are seated, and as with the upper end surface 51, is a circular planar lower end surface 53.

The hole 54a of the valve seat 50 connects the seating surface 52 and the lower end surface 53, and forms a valve seat flow path 54 in which the transport fluid flows. As shown in fig. 4 and 5, a gas retention section 53a in which gas in the transport fluid is retained is formed between the valve seat flow path 54 and the lower end surface 53. The seat flow path 54 is formed in a predetermined shape such as: the horizontal distance L from the central axis P perpendicular to the lower end surface 53 to the valve seat passage inner peripheral surface 55 excluding the seating surface 52 and the lower end surface 53 is not constant over the entire circumference (360 ° range) of the valve seat passage inner peripheral surface 55 of the valve seat passage 54.

As shown in fig. 3, the predetermined shape of the seat flow path 54 is preferably: the difference between the maximum value Lmax and the minimum value Lmin of the horizontal distance L from the central axis P over the entire circumference of the seat channel inner circumferential surface 55 of the seat channel 54 is, for example, 10% to 30%, and preferably 15% to 20% of the maximum value Lmax. The seat flow path 54 shown in fig. 2 to 5 is formed in an elliptical shape when viewed in a horizontal cross section.

Here, the seating surface of the general valve seat and the valve seat flow passage are formed in concentric circles. Therefore, if the pump device is operated in a state where the gas is retained below the valve seat or in the gas retaining portion, the gas diffuses in a ring shape around the entire circumference of the inner circumferential surface of the valve seat flow passage below the valve ball and lifts the valve ball.

In this case, the force for lifting the valve ball is dispersed over the entire circumference, and as a result, when the amount of gas mixed into the fluid to be transported is large, the compressive force of the fluid to be transported by the pump device becomes insufficient, and a gas lock state is often formed.

In contrast, in the valve seat 50 of the present embodiment, the

valve balls

31a and 31b and the seating surface 52 are completely sealed, and the valve seat flow passage 54 is formed in a shape in which the diameter is not constant over the entire circumference of the valve seat flow passage inner circumferential surface 55 as described above. Therefore, when the gas staying in the carrier fluid below the valve seat 50 is collected in the gas staying portion 53a and the gas rises from the gas staying portion 53a through the valve seat passage 54, the gas is concentrated and rises toward the valve seat passage inner peripheral surface 55 side where the horizontal distance L is the maximum value, as compared with the valve seat passage inner peripheral surface 55 side where the horizontal distance L is the minimum value.

Thus, even if the compression force of the fluid to be conveyed by the fixed displacement pump 1 is small, the

valve balls

31a and 31b seated on the seating surface 52 of the valve seat 50 can be sufficiently lifted by the gas passing through the valve seat flow path 54 at the local position, and therefore the gas can be discharged in the direction of the valve guides 32a and 32 b. Therefore, according to the valve seat 50 of the present embodiment, the occurrence of gas lock can be effectively prevented while maintaining the sealing performance of the

valve balls

31a and 31 b.

Here, the reason why the difference between the maximum value Lmax and the minimum value Lmin of the horizontal distance L from the central axis P is 10% to 30% of the maximum value Lmax is adopted for the predetermined shape of the seat flow path 54. That is, when the difference between the maximum value Lmax and the minimum value Lmin of the horizontal distance L is large, the minimum value Lmin must be set small in order to ensure the sealing performance between the valve seat 50 and the

valve balls

31a and 31b, and in this case, the area of the valve seat flow path 54 is reduced as a result. Further, when the flow path area is small, the impedance becomes large when the transport fluid flows through the valve seat flow path 54, which is not preferable from the viewpoint of pump performance.

On the other hand, when the difference between the maximum value Lmax and the minimum value Lmin of the horizontal distance L is small, the effect of concentrating the gas toward the seat passage inner peripheral surface 55 side where the horizontal distance L is the maximum value Lmax is reduced below the

valve balls

31a and 31b as described above, and in this case, the effect of preventing the occurrence of gas lock is reduced as a result, which is not preferable. Therefore, as a result of experiments conducted with great effort by the present inventors in order to improve the effect of preventing the occurrence of gas lock while considering the influence on the pump performance, it is inferred that the difference is "10% to 30% inclusive", and preferably "15% to 20% inclusive", with respect to the maximum value Lmax.

As shown in fig. 6 and 7, the valve seat holder 40 is formed to have a cylindrical outer appearance by supporting the lower end surface 53 of the valve seat 50 disposed at the lowermost position of the suction valve 10A and the discharge valve 10B, and has a recessed fitting portion 41 fitted to the lower side of the housing 30B. The bottom surface of the fitting portion 41 constitutes a support surface 42, and the support surface 42 supports the lower end surface 53 of the valve seat 50 by surface contact.

The seat holder 40 connects the support surface 42 with the lower end surface 43 and conveys a fluid therethrough, and the seat holder 40 has a holder flow path 44 communicating with a seat flow path 54 of the seat 50. The seat flow path 44 has a central axis P identical to the central axis P of the valve seat 50. The holder flow path 44 has a plurality of ribs 46 projecting from the holder flow path inner peripheral surface 45 toward the center axis P and extending along the center axis P.

In the valve seat support 40 configured as described above, when the gas in the transport fluid fed from below the valve seat support 40 rises through the support flow path 44, the gas does not spread annularly over the entire circumference of the support flow path inner circumferential surface 45, but concentrates and rises toward the portion between the respective protrusions 46. Further, the gas concentrated at a local position between the respective ribs 46 of the seat flow path inner peripheral surface 45 forms a plurality of flows and enters the gas retention portion 53a of the valve seat 50, and rises through the valve seat flow path 54.

In this way, the flow direction of the gas staying in the gas staying portion 53a of the valve seat 50 in the seat flow path 44 of the valve seat 40 is secured by the ridge 46. This enhances the effect of using the valve seat 50 alone, and the gas is diffused annularly over the entire circumference of the valve seat flow path inner circumferential surface 55 of the valve seat flow path 54, and as a result, it can be expected that the force for lifting the

valve balls

31a and 31b is more reliably prevented from being dispersed. Thus, if the seat holder 40 having the holder flow path inner peripheral surface 45 formed with the ridge 46 is used, the operational effect of the seat 50 of the present embodiment can be further improved.

Fig. 8 to 15 are plan views showing modifications of the valve seat 50. Although the above-described valve seat 50 includes the valve seat flow passage 54 having an elliptical shape when viewed in a horizontal cross section, the valve seat 50 may include the valve seat flow passage 54 having the following shape when viewed in a horizontal cross section. That is, the seat flow path 54 may be formed in any one of a water drop shape shown in fig. 8, a notched shape (partially deformed circular shape) shown in fig. 9, and a snare drum shape shown in fig. 10, respectively, when viewed in a horizontal cross section.

The seat flow path 54 of the seat 50 may be formed in any one of an eccentric shape (eccentric circular shape) shown in fig. 11, a spectacle shape (superimposed circular shape) shown in fig. 12, a cross shape shown in fig. 13, a square shape (rectangular shape) shown in fig. 14, and a triangular shape shown in fig. 15, respectively, when viewed in a horizontal cross section.

In any of the above-described shapes, since the diameter of the valve seat flow path 54 is not constant over the entire circumference of the valve seat flow path inner peripheral surface 55, the gas is concentrated and rises toward the valve seat flow path inner peripheral surface 55 side where the horizontal distance L is the maximum value, as compared with the valve seat flow path inner peripheral surface 55 side where the horizontal distance L is the minimum value, and therefore, the occurrence of gas lock can be effectively prevented while maintaining the sealing performance of the

valve balls

31a and 31b as described above.

While embodiments of the present invention have been described above, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. The novel embodiments of the present invention can be realized in various other forms, and various omissions, substitutions, and changes can be made without departing from the spirit of the present invention. These embodiments and modifications thereof are included in the scope and spirit of the invention, and are included in the invention described in the scope of claims and the equivalent scope thereof.

For example, in the above-described embodiment, the shape of the valve seat flow passage 54 of the valve seat 50 is an elliptical shape or the like when viewed in a horizontal cross section, but in addition to this, any shape may be employed as long as the horizontal distance L from the center axis P to the valve seat flow passage inner peripheral surface 55 excluding the seating surface 52 and the lower end surface 53 is not constant in diameter over the entire circumference of the valve seat flow passage inner peripheral surface 55 of the valve seat flow passage 54.

Description of the reference numerals

1 constant delivery pump

2 drive shaft

4 diaphragm

5 Pump head

5a suction inlet

5b discharge port

6 pump chamber

8. 9 connecting port

10A suction valve

10B discharge valve

20A, 20B connection adapter

29A, 29B joint

30a, 30b housing

31a, 31b valve ball

32a, 32b valve guide

40 valve seat support

41 fitting part

42 support surface

43 lower end surface

44 seat flow path

45 seat flow path inner peripheral surface

46 projecting strip

50 valve seat

51 upper end surface

52 seating surface

53 lower end surface

54 valve seat flow path

55 valve seat flow path inner peripheral surface

Claims

1. A valve seat disposed below a valve ball, characterized in that,

is formed of an annular member having a hole in the center, the hole serving as a flow path through which a transport fluid flows,

is arranged such that the central axis of the hole portion is directed in the vertical direction,

a seating surface connected to an upper end of the hole portion and a lower end surface connected to a lower end of the hole portion, the seating surface conforming to an outer shape of the valve ball and on which the valve ball is seated to form a complete seal,

the hole is formed in a predetermined shape in which a horizontal distance from the central axis to an inner circumferential surface of the hole is not constant over an entire circumferential range of the inner circumferential surface of the hole.

2. The valve seat according to claim 1, wherein the predetermined shape is a shape in which a difference between a maximum value and a minimum value of the horizontal distance over an entire circumference of an inner circumferential surface of the hole portion is 10% or more and 30% or less from the maximum value.

3. The valve seat according to claim 1 or 2, wherein the prescribed shape is any one of a partially deformed circular shape, an elliptical shape, a water drop shape, a snare drum shape, an eccentric circular shape, an overlapped circular shape, a cross shape, a square shape, and a triangular shape when viewed in a horizontal cross section.

4. A valve structure is provided with: a valve ball, a valve seat disposed below the valve ball, and a valve seat support supporting the valve seat,

the valve seat is characterized in that:

is formed of an annular member having a hole portion at the center, the hole portion serving as a valve seat flow path through which a transport fluid flows,

the seat holder having a holder flow path communicating with the seat flow path,

the hole is formed in a predetermined shape in which a horizontal distance from the central axis to an inner peripheral surface of the hole is not constant over an entire circumferential range of the inner peripheral surface of the hole,

the holder flow path has a plurality of ribs projecting from an inner peripheral surface of the holder flow path toward the center axis at equal intervals and extending along the center axis.

5. The valve structure according to claim 4, wherein the predetermined shape is a shape in which a difference between a maximum value and a minimum value of the horizontal distance over an entire circumference of an inner circumferential surface of the hole portion is 10% or more and 30% or less than the maximum value.

6. The valve structure according to claim 4 or 5, wherein the prescribed shape is any one of a partially deformed circular shape, an elliptical shape, a water drop shape, a snare drum shape, an eccentric circular shape, an overlapped circular shape, a cross shape, a square shape, and a triangular shape when viewed in a horizontal cross section.

7. The valve structure according to claim 4 or 5,

two valve balls are arranged up and down,

the valve seats are respectively arranged below the valve balls,

the valve seat support supports the lower end face of the valve seat below.

8. The valve structure of claim 6,

two valve balls are arranged up and down,

the valve seats are respectively arranged below the valve balls,

the valve seat support supports the lower end face of the valve seat below.